LCD TFT sign for on-board use in public transportation
View Patent ↗An LCD destination sign is provided that provides a high resolution image and operates in at least two modes. One mode is a destination message mode that is used when a destination message (i.e., a route number and/or destination name in substantially static alphanumeric or symbols) is to be displayed on the destination sign. The second mode is a non-destination mode wherein graphic images are displayed on the destination sign, wherein such graphic images do not provide a destination message and may include video feeds, weather forecasts or newsreels.
1. A destination sign comprising:
a front bezel assembly comprising:
a bezel front side;
bezel side walls extending backwards from the periphery of the bezel front side to establish a bezel enclosure about a bezel backside; and
an aperture through the bezel front side to the bezel backside, the aperture having a width to height ratio of between about 8:1 and 4:1;
a transparent cover sheet positioned against the bezel backside and covering the aperture;
a color LCD display panel mounted within the bezel enclosure and behind the transparent cover sheet such that a display surface of the color LCD display panel faces the aperture, the display surface having an aspect ratio of between about 8:1 and about 4:1, the color LCD display panel adapted to produce a first image at a first resolution;
a backlight assembly, positioned within the bezel enclosure and behind the color LCD display panel such that an illumination surface of the backlight assembly faces the aperture, the illumination surface comprises an array of red, green and blue LEDs adapted to produce a first illumination output comprising the first image at a second resolution wherein the second resolution is the same as or a lower resolution than the first resolution and adapted to produce a second output comprising substantially white light;
a graphic data bus, connected to the color LCD display panel, adapted to provide a first graphic data signal, the first graphic data signal comprising the first image formatted for display on the color LCD display panel; and
a mode signal connection adapted to provide a mode signal to the backlight assembly, wherein when the mode signal indicates a destination message mode then the first output is produced on the illumination surface, and wherein when the mode signal indicates a non-destination message mode then the second output is produced on the illumination surface.
2. The destination sign of claim 1 , further comprising a mode select circuit adapted to receive the mode signal and the first graphic data signal, the mode select circuit further adapted to provide a second graphic data signal to the backlight assembly when the mode signal indicates a destination message mode, the second graphic data signal comprises the first image formatted for display on the illumination surface.
3. The destination sign of claim 2 , wherein the mode select circuit is further adapted to provide a third graphic data signal to the backlight assembly when the mode signal indicates a non-destination message mode, the third graphic data signal indicates that the illumination surface shall produce white light.
4. The destination sign of claim 2 , wherein the mode select circuit is further adapted to provide a fourth graphic data signal to the backlight assembly when the mode signal indicates a non-destination message mode, the fourth graphic data signal indicates that the illumination surface shall produce locally dimmed white light.
5. The destination sign of claim 1 , wherein when the mode signal indicates the destination message mode then the first output is produced on the illumination surface in white light, the first output consisting of a destination message.
6. The destination sign of claim 1 , further comprising a housing, the housing comprising:
a housing backside;
housing sidewalls extending forward from the periphery of the housing backside to establish a housing enclosure such that the front bezel assembly interfits within the housing enclosure with the aperture facing forward; and
means for mounting and adjusting a viewing tilt angle of the front bezel assembly.
7. The destination sign of claim 1 , wherein the mode signal is adapted to indicate the destination message mode when the first image consists of a destination message.
8. The destination sign of claim 1 , wherein the mode signal is adapted to indicate the non-destination message mode when the first image is a non-destination message or an image that is part of a moving video image.
9. The destination sign of claim 1 , wherein the illumination surface comprises an array of clustered red, green and blue LEDs in an array capable of producing illumination images having a resolution ranging from about 10% to 100% of the display resolution of the color LCD display panel.
10. The destination sign of claim 1 , wherein the array of red, green and blue LEDs is an array of tri-colored LEDs.
11. The destination sign of claim 1 , wherein when the mode signal indicates the destination message mode, the combination of the first image on the LCD display panel and the first illumination output on the illumination surface produces a visual destination message that meets or exceeds the American Disabilities Act requirements for destination and route signs.
12. The destination sign of claim 1 , wherein the destination sign is adapted for mounting on an interior surface of a public-transit vehicle.
13. A destination sign comprising:
a color LCD display panel comprising a front display area having an aspect ratio of between about 8:1 and about 4:1, the color LCD display panel adapted to produce a first image at a first resolution;
a backlight assembly, positioned behind the color LCD display panel such that an illumination surface of the backlight assembly faces a backside of the color LCD display panel, the illumination surface comprises an array of clustered red, green and blue LEDs adapted to produce a first illumination output comprising the first image at a second resolution wherein the second resolution is the same as or a lower resolution than the first resolution and adapted to produce a second illumination output comprising substantially white light;
a graphic data bus, connected to the color LCD display panel, adapted to provide a first graphic data signal, the first graphic data signal comprising the first image formatted for display on the color LCD display panel; and
a mode signal connection adapted to provide a mode signal to the backlight assembly, wherein when the mode signal indicates a destination message mode then the first output is produced on the illumination surface, and wherein when the mode signal indicates a non-destination message mode then the second output is produced on the illumination surface.
14. The destination sign of claim 13 , further comprising a mode select circuit adapted to receive the mode signal and the first graphic data signal, the mode select circuit further adapted to provide a second graphic data signal to the backlight assembly when the mode signal indicates a destination message mode, the second graphic data signal comprises the first image formatted for display on the illumination surface.
15. The destination sign of claim 14 , wherein the mode select circuit is further adapted to provide a third graphic data signal to the backlight assembly when the mode signal indicates a non-destination message mode, the third graphic data signal indicates that the illumination surface shall produce white light.
16. The destination sign of claim 14 , wherein the mode select circuit is further adapted to provide a fourth graphic data signal to the backlight assembly when the mode signal indicates a non-destination message mode, the fourth graphic data signal indicates that the illumination surface shall produce locally dimmed white light.
17. The destination sign of claim 13 , wherein when the mode signal indicates the destination message mode then the first output is produced on the illumination surface in white light, the first output consisting of a destination message.
18. A method of displaying a destination message on a backlit LCD destination sign, wherein the backlit LCD destination sign comprising a color LCD display panel and backlight assembly adapted to backlight the color LCD display panel, the method comprising:
receiving a first image signal by the backlit LCD destination sign;
determining, by a mode select circuit, whether the first image signal is for a destination message image or a non-destination message image;
when the mode select circuit determines that the first image is for a destination message image, then simultaneously displaying the destination message image on the color LCD display panel and on the backlight assembly;
when the mode select circuit determines that the first image is for a non-destination message image, then displaying the non-destination message image on the color LCD display panel and illuminating the backlight assembly to produce substantially white light.
19. The method of claim 18 , further comprising receiving a mode signal by the mode select circuit, the mode signal indicating that the backlight assembly is to be placed in a destination message mode or in a non-destination message mode, wherein when in destination message mode the destination message image is simultaneously displayed on the color LCD display panel and on the backlight assembly.